HyperShield Back Cover for iPad 2nd/3rd/4th Generation (GRAY) Covers the iPad (2nd, 3rd, 4th generation) aluminum back Only 1.4mm thin. You will hardly notice it Made of durable TPU (Thermoplastic Polyurethane) Shock absorbing gel-like property protects iPad from bumps & scratches Unlike silicon, TPU retains shape, form and color even after repeated use